Lee's initial Doom 2 work made a passing grade but wasn't too mindblowing. Included were his X-Fire deathmatch series along with single level contributions to The Darkening Episode 2, 10 Sectors, and Alien Vendetta. As he was leaving the Doom community in 2004, Anthony Soto released a small WAD of leftover maps named End Game. I wasn't expected much from a thrown-together assembly of some authors' forgotten work. But amongst the heap was Lee's awesome all-new level, 'Water Treatment Facility'. The Ultimate Doom episode 4 orange sky and post-industrial theme make this reminiscent of Quake 2 and Parallel Team's Fragfest Initialized.

On the technical side, the first thing to note is that it works in doom2.exe. No visplane overflows or HOM glitches which is an accomplishment given the level of detail in view at all times. The layout itself is compact, but areas are traversed multiple times. This isn't depth-first search (as found in most user-created WADs) since the design is more organic. The non-linear layout allows for a different gaming experience over multiple sessions. The best part about revisiting areas are the visual changes as the level progresses. Platforms raise out of the water, stairs build to allow new paths, and elevators lower to reveal power-ups. All four secrets are clever; especially one that raises water in the main outdoor pit to reach rockets in an elevated alcove.

Doom isn't capable of room over room, but Lee plays with sky heights to make the space look more 3D than it really is. It's similar to techniques used in his Crucified Dreams level (MAP11: 'Tarantism', which I named after a song by The Mars Volta.) Variable sector heights with a sky ceiling and strategically-placed architecture stretch the base engine to its creative limit. Lee also makes heavy use of every known lighting effect in the Doom engine. ukiro-style smooth lighting, floors/ceilings with different light levels, and crates casting vertical shadows are all present but again, this is the vanilla engine. To display these effects before End Game's release, Lee released four doom2.exe-compatible demo WADs: 3D Examples, Split Door, Elevator, and Lighting Effects. Some room-over-room work is a fancy derivative of Iikka Keränen 3D special effects demos dated 1998. Given all the tech speak, the gameplay is quality enough that these effects never look or feel gimmicky.

It's a shame this wasn't released on its own or in a more renowned project since End Game is pretty much a B-sides WAD dump.

I feel obliged to include a level from this seminal release. This is the first Doom map with a double 3D bridge. Iikka faked a room-over-room effect and he originated the use of instant moving sectors with invisible floors by using unexpected behaviour in certain Doom 2 linedef trigger types. This led to the development of horizontal swinging and/or sliding doors along with the later implementation of voodoo doll scripts for the Boom-compatible source ports. His bridge design was later dwarfed by Jonas "Chrozoron" Feragen's Hell Revealed II: MAP19 five-story take.

In the map's design, you can see many nods to Iikka's other levels in the series. Ashy walls with wooden supports (MAP09, which was before released as mines.wad), platforms leading to small elevated stucco buildings windowed with gothic trims (MAP06), streams cutting through the middle of the level with a bridge to get across (MAP06), a red stoned tower leading to a switch (MAP02, MAP06), and narrow indoor areas connected by white-railed stairways (MAP07). These are a stepping stone for developing a design language, with all these elements appearing in Requiem MAP08, MAP13, MAP16, and MAP22, making that WAD almost a homage to Dystopia 3.

This leads us to Iikka's entry to Requiem which was unorthodox given his wadography. This is where you see Quake's colour schemes and architecture leaking into his designs. Addictive Deathmatch Series, released five months after Dystopia 3, made exclusive use of brown brick textures trimmed by dark metal and aged green stone. Requiem followed a few months later, although most authors created their levels before Addictive. These early levels had obvious nods to Dystopia 3. This MAP03 and secret level MAP31 (a Doom 2 remake of Quake E1M6 "The Door to Chthon") also use a dark custom texture set in line with the tenebrism of Quake's engine. Harsh shadows in the texture design and creative geometry gave a look and feel nobody had done before in the Doom engine. This was the forerunner to the GothicDM series (which Iikka also contributed to).

The best Doom 2 levels get inspiration from Doom Episode 1 by giving glimpses of where the author will lead the player to. But don't just let them loose to explore every possible branch when starting from the root. Completely non-linear layouts such as Polygon Base feel too sloppy. I'd rather have controlled pathways with some foreshadowing. "Poison Processing" pulls this off by placing pillars and access bar doors as barriers to allow full view of rooms and alcoves. Near the start, you can see the exit door past a wooden fence but it takes a good 15 minutes until they traverse the map to arrive at that room.

The level setting itself is predominantly underground in a sewer environment, following prototypical medieval designs with a central canal and elevated side walkways. There are embellishments involving waterfalls and walkway steps to create vertical enemy fights that are visually appealing. This sector usage became a new focus for Iikka, with side areas of Addictive also including sewers hallways. Brown brick perpendicular church designs inspired by Quake make an appearance near the end and they became the main theme of his GothicDM levels.

You can see where he was coming from considering the Quake add-on levels Iikka was making in parallel to his final Doom productions. The wavy red imp teleporter used after a sewage treatment room is an ode to Quake's slipgates. He allowed darker themes to leak into Doom's palette, eliminating the vibrant colour of Knee Deep in the Dead's texture set.

On the surface, it seems Ola's Tantrum 2 or Venom would be more sensible entries to this list. But I think his last single player map for The Darkening Episode 2 is a more realized work. The layout is well thought out and texture schemes are consistent through every room and structure. It also contains some of his trademark smoothed lighting, which was as influential on my work as John Bye's The Darkening Episode 1 MAP08 ('Discordia'). The level title "Toxicity" predates System of a Down's song pun by more than a year and deathmatch entry MAP16 "Devastation" was also named before Quake 3: Arena's map of the same name. Ola, truly a Swedish icon.

The first room establishes the use of shooting puzzles to advance to the next goal. Distant switches required to a gunshot to trigger a door to open. Otherwise, flow is straightforward with keycards and switches used. The layout is linear with a few choices in path and optional side quests to reward the player with power-ups. Interconnectivity of the rooms make this layout much tighter than your usual linear Doom 2 level. Since it is the last single player level in the set, difficulty gets ramped up. This is especially apparent toward the end with a close quarters Cyberdemon fight followed by a large-scale outdoor plasma skirmish. More than a dozen arachnotrons and a Spider Mastermind? Alrighty. The design finds a decent balance between claustrophobic punch-outs and open courtyard rocket fights.

The setting is a mix of Quake 2 industrial base and Doom Episode 1, along with the sewer areas inspired by the aforementioned Requiem MAP03 ("Poison Processing").

Of course, Ola made all the custom textures used on every surface in sight. Bright cement contrasts rusted industrial metals. Computer panels, crates, and decorative logos littering the environment. A wide range of colours get used while still staying coherent for each adjacent room. It's even more consistent than some professional designers (hi Sandy Petersen.)

After more than a dozen levels since 1995, this fellow Canuck started the Chord series. The first two entries were forgettable due to the mish-mash of visual themes and symmetrical layouts, likely a result of The Talosian Incident's influence, which Malcolm contributed to. With the series' third entry, Chord NG, the theme went from non-sequitur Doom episode three toward Quake-inspired realism. Architecture makes physical sense in his dimly-lit techno-hell fortification. Malcolm took one short foray into Quake mapping but returned to the Doom community, permitting these outside influences to bleed in.

Following Chord NG, Malcolm took part in Gothic Deathmatches 2, pushing architectural detail to new highs not before seen in vanilla Doom. No surface can remain barren. With Chord G, he was at his creative peak. Gameplay worked around the environment rather than the longheld opposing mantra of community members. The fun factor didn't suffered to a point of distaste as, say, deathmatch WAD Gothic 99. Malcolm was more interested in difficult fights within claustrophobic areas. That he provides, with constant baron fights in tight quarters leading to many necessary savegame reloads.

For this fourth Chord level, everything takes place underground without natural sky lighting sneaking in. This concept wasn't anything new as indicated by his No Sun series and contributions to The Talosian Incident. Dark quarters like this reminded me of catacombs, specifically Edgar Allan Poe's short story The Cask of Amontillado. There are elements of terror surrounding damp, underground man-made structures constructed only for death.

Malcolm uses prototypical contrasting textures of green marble supported by rusted metal beams and pillars. He showed remarkable consistency in marble structure proportions. For any 32 unit high texture usage, the depth of the beam was also 32 units wide. You can note a riblet design where large marble cross-beams lock to the ceiling using narrowly-spaced repeating metal attachments. You can see this prototype pop up again and again after this WAD release. While his previous layouts were square, here he stressed 45 degree angles to cause a smoother flow. No jagged wall edges to prevent player movement. Outside the submerged building, jagged sandstone wall with rock floors are starkly contrasted. Torch lighting and surrealist lighting diminishes into dark caverns beyond. More in-tune with building consistent and realistic environments, Malcolm transformed into a complete designer. So much so, he the community voted him into the Doomworld's Top Ten Doom Level Makers contest held in 1998.

Now Malcolm confounds us further by naming the series' fifth entry Chord 3. It follows since this level uses texture schemes more similar to Chord 1/2. Chiseled wood and stucco walls mix with corroded trimmings the Doom community has become so familiar with. Why are id software hells so comparable to pre-industrial Europe? Recalling railways and prefabricated warehouses?

There are still hints of Chord G seeping in with the green marble and an underground theme. But there is now red-hot rocks and a more threatening atmosphere compared to warmer tones of the former. You can see Malcolm getting stuck into micro-details by carving architecture around stock Doom II textures (see: WOOD5). It's a chicken/egg situation as I saw Matt Dixon, a playtest buddy of Malcolm's, performing the same editing tricks around this time (see: Gothic 99).

The layout involves a fair amount of passing through areas many times to attain keys and the like. This is in a more circular manner than a linear search. The finale displays his love for a delayed lowering lift setpiece. You may have seen this in Quake's E2M6 "The Dismal Oubliette". He also used the effect in Chord NG as a method to force you into dealing with baddies rather than speedrunning around. Like me... in God mode.

The quality of this level is comparable to Chord G. It acts as a proper send-off for Malcolm Sailor's Doom editing career.

Eternal Doom's 32 single-player map collection was an exercise in tedium. Its massive layouts contain ineffective switches requiring traversal from one side of the map to the other. Sverre's work emitted the few beams of light in an overwrought experience. His custom textures and three levels were many cuts above Team TNT's otherwise middling releases of Final Doom: Evilution, Daedalus, Icarus, ...you get the picture.

"Dark Dome" was his masterwork for the Doom engine before going pro to work on Redneck Rampage, KISS: Psycho Circus, and Anarchy Online.

He used a strong colour scheme that was Hexen-esque. Black/blue against grey/brown with a few areas containing green and yellow shades. They represented natural colours for his huge castle, complete with a moat (well, abstractly) and a rising bridge required to cross.

Like other entries in the set, you may end up wandering the level for hours. You must search out a series of switches required for access to the yellow key. This is perhaps a holdover from Quake's "# switches remaining" puzzle. The difference from others in Eternal Doom is that you are previewed these switches before becoming aware what they're for. A smart player will use Doom's automap marker functionality to note these yellow skulls. Once reaching the blocked yellow key, retreat systematically to flip every switch and raise the fountain upon which the yellow key sits.

Paths themselves are a series of walkways and tight hallways connecting a main, brightly-lit corridor and its bordering rooms. It can feel a labyrinth with falling floor traps and barred see-through doors leading you to search down more obscure branches. It's an absolute behemoth of a level that effective holds your attention in a striking setting for its full duration.

Chris Lutz has an eye for obscene detail. It's to the point you can imagine the build process takes dozens of hours for one measly 2.5D map. After releasing an Inferno episode replacement, Chris decided to remake classic episode one of Doom. He stressed more realism rather than abstract structures of the original game. E1M1 is actually a hangar and its crashed spaceship recalls malfunctioning vehicles at the start of Dystopia 3's levels. For E1M3, Chris created a large-scale crane with an accurate long shadow cast on the mud below. This realism is a continuation of his work on Chaos Crews' Caverns of Darkness where logically laid out buildings are seamlessly integrated through stone walkways, railways, doorways, and 99 Ways to Die.

Roger Ritenour attempted to reach similar goals in Earth and Phobos through clever texture-work and doom.exe compatibility. But their limitations were obvious to a trained eye. Chris extended these concepts by using complex sectors to attain a multitude of Boom effects including but not limited to: vertical shadows, dynamite blasts, empty pools dynamically filling with submergable water, instantly destroyable walls, floating items (e.g., crates) having their heights variate in real-time, fake 3D floors, and horizontally moving fan blades (hey!).

He takes architectural cues Quake 2 such as large rooms experiencing structure damage (caved in ceilings, cracked pipes, smashed translucent windows.) Futuristic beam/pillar designs support the nostalgic Doom episode one texture selection of cold cement and smooth sheet metal contrasted by dark iron. This level also defines this PWAD as one of the few add-ons to provide complete continuity of secret level E1M9 leading into a devilishly clever train traversal for E1M4.

Chris has since released a Doom 2 MAP29 remake, The Dying End and he planned a Doom episode 2 replacement to round out his trilogy. Unfortunately, it looks like the last update on Deimos: Anomaly Unleashed was from July 2004. We can only hope he returns to follow through.